Wednesday, May 09, 2007

How T1 Lines Support VoIP Telephony

T1 lines have long been the preferred trunking option for traditional PBX business telephone systems. But how do T1 lines support enterprise level VoIP phone systems?

Many medium and large companies are augmenting their legacy PBX phone systems with VoIP, wiring new installations as converged voice and data or even going so far as "fork lift upgrades" when the older system just isn't economical to upgrade anymore. The well-documented reasons for this trend are enhanced features that improve employee productivity, cost savings by converging both computer and voice networks into a single LAN, and ease of moves and upgrades. But one thing hasn't changed. That is the need to connect to the PSTN or Public Switched Telephone Network.

The PSTN, the common denominator in universal telephone service, is still a largely analog and TDM (Time Division Multiplexing) based system. Smaller organizations with need for only a few outgoing lines will likely find that standard analog business lines make the most sense for their limited key telephone systems and small PBX or IP PBX systems.

An opportunity develops when the business grows to the point where it needs 6 to 12 outgoing lines and a broadband Internet connection. At that point, T1 Integrated service starts to be more cost effective than multiple analog lines and a separate broadband service. A device called an IAD or Integrated Access Device connects to both the phone system and the network router to provide voice and data service. The Integrated T1 line feeds the IAD and may even dynamically assign bandwidth so that broadband speed is maximized when there are few or no phone calls in progress.

Enterprise VoIP systems use IP phones or ATA analog telephone adapters to connect the phones to the corporate LAN. All internal calls are handled by the system and incur no telephone company charges. Point to point T1 lines extend the LAN to connect other business sites into a single large network. VoIP calls transverse this WAN (Wide Area Network) connection, as do site to site data transfers.

T1 trunk lines are needed for the inevitable calls outside the organization. A corporation and its suppliers and major customers may be connected on an Intranet to transport voice and data. For connection to the outside world, calls have to be terminated to the PSTN. A voice gateway performs the conversion between the packet and switched networks. A single T1 trunk offers up to 24 individual telephone lines. The T1 PRI variant offers 23 lines plus a signaling and data channel that can speed call connections and offer services such as Caller ID. The T1 or T1 PRI line connects to the phone service provider to offer incoming, outgoing, local, long distance, or any combination of these phone services.

Do you use T1 lines to transport your PBX or IP PBX outside calls? If so, our expert consultants would like to save you money on your T1, Integrated T1, Point to Point T1 or T1 PRI service as soon as possible. Get an instant online quote or talk to an T1 line expert right now at T1 Rex.

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